I guess that in the early stages of your idea your in a way going to have to be selling the inventories anyway, not going to be easy to build both sides of the market without some legwork on your part. One of the advantages to being small I guess is you can actually go above and beyond to broker deals rather than only having time to really be doing it passively through a webapp.

Great point. It'll be a solid way for me to gain some domain expertise at the same time.

Marketplaces often flop when the people who build them don't fully understand the market they're facilitating.

I think the exercise in the brokering of selling newsletter ads, even on a small scale of one or two customers, will be truly valuable in achieving understanding of the needs of the platform before you dump precious time and resources into building it.

I wouldn't write off that idea too quickly... As an added bonus you can make $$ doing this from day 1, before you even have a product.

Great points.

1.) It gave me a realization that I may not be the best person to execute this, but I can sure as hell give it a shot.

2.) I can do this in the short term to prove there's an issue, but it's not scalable.

With that being said, I'm still going to pursue this in order to prove concept and make some cash.

What is this 'wrong person to execute' nonsense? You're only limited by your imagination and ability work hard towards your goal. I'll take passion over expertise any day.

I guess it come from reading investor's startup blogs. I'm going to do the 37 signals thing and try to do as much as I can until it's not physically possible.

If I was raising investment (plan Z), I'd try to find a team member with ad sales experience (or maybe an advisor).